Improvement in car-trucks



G. H. GRIGGS.

Patented June 21, 1870.

Car Truck.

No. 104,580.V

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Letters Patent No. 104,580, dated June 2l, 1870.

IMPRQVEMENT IN CAR-frauexes.A

The sehedulereferred to in these LettersPatent and making part cf thesame. t

To all `fzt'hoia may concern.:

Be v,it known that I, GEORGE H. Games, of Woreester, in the county ofWorcester' and State of Massachusetts, have invented certain new anduseful Imswinging mot-ion.

I provide a very c flieientand ncarl y constantV friction, which, whileit"does not prevent thennovement of the swing-beam, and, consequently,of the car, from side to side to the fullest extent which is allowed by`the construction in other respects, or which is desired in any case, somodifies the Swinging mot-ion that it is almost immediately arrested,`and the 'consequence is a smooth and comparatively steady motion,instead of a succession of free'swings.

I will rst describe what I consider the best means of carrying outmyinvention, and will afterward designatethe pointswhichI believe to benew therein.

The accompanying drawing forms a part of this specicatiou.

AFigure 1 is a longitudinal section on the line S S in fig. 2. i

Figure 2 is a plan view.Iv

These figures show the novel parts of an entire truck, with so much ofthe other parts as seem necessary to show their relation thereto.

Figures 3 and 4 are face views of two forms of some vof the parts; and

Figure 5 is a vertical section through Some of the `parts on -a largerscale.

i Similar letters of reference indicate like parts in all the figures.'

What is known as the swing-beam or swing-motion in car-trucks,originally patented -by Davenport d'. i Bridges in 1844, is toofamilial' to mechanics to require a detailed description. The drawingrepresents one of thc most approvedforms.

A is the main framing of the truck, the runninggcar of which is notrepresented.

Al A2 are the cross-sills, frequently known as logs, and I will so termthem. They form a part of the rigid frame-work of the truck, and extendacross immediately forward and behind thc cross-timber B, which is theswing-beam, and upon which, the weight `of one end of the car-body issupported and carried in the ordinary manuel'. g

C C are springs 1 1), the sand-plank; and

E Ethe slings or vibrating links which holdup the `sand-plank, and withit, through the aidof the springs C C, theswiig-bcam B, and the loadcarried thereon,

so that the Swing-beam Il and its connections are allowed to swing ti'omsideto side in the truck.

'lhcre may be springs, not rcpresented to recieve and check the sidemotion of the swing-beam B, by receiving its impact directly, it'desired.

My invention allows of all ordinary modifications and improvcnicnts inregard to the details, which it is needless to enumerate.

It is common to apply the logs A* A2 close to the swing-beam l, so thatit is liable to rubagainst them as it swings from vSide to side; but ifthe parts are tittcd with absolute parallelism, and thebeam B is made tofill the space with absolute accuracy, so as to induce a reliableli-iction at first, the change of form of the parts ducto springing andwarping, the shrinkage of the wood, andthe wear of the rubbing-snriiiceswould soon materially change the conditions.

Every change ofthe forward motion, and particularly every obstacleencountered ou the track, is liableto induce a strong movement of thecar forward or backward, relatively to the truck. To resist this, verycicient bearing-surfaces must be provided, to allow thc swing-beam B topress forward and backward with great force, wit-hout inducing damage tothis or any of the other parts.

It has been proposed to introduce springs to control the movement oflthe swing-beam forward and backward I do this, and more. v

The springs previously employed or proposed in such positions andrelations, allowed the swing-beam to'move freely from side to side. Thesprings did not induce resistance to such motion. I have providedsprings so arranged that they will yield slightly forward and backwardto soften any shocks iu that direction, but this is only one of theirfunctions. Another, which I esteem vastly more important, is' theresistance and rapid extinguislnncnt of the swinging motion of the beam.

I provide rubbing-pieces or broad shoes on my springs, which bear fairlyand uniformly against corresponding rubbing-plates on the adjacentsurfaces, and thc'friction induced by the tension of my springs isdeveloped between the shoes and rubbing-plates to induce a uniform andreliable resistance, which rapidly kills the swinging motion. I,.In easean irregularity in the track, or any other cause, has induced a suddenmovement of thc truck to one side, or in case, for any reason, the carhas been suddenly and violent-ly moved to one side on the truck and'thenliberated, the ordinal-)t arrangements allow prolonged series of swings.The swingbeam,.with the load attached, swings back to its normalposition, and, with the momentum thus acquired, moves much beyond it,then swings back again nearly to its first extreme position, and asuccession of such swings oeA eur before the position of rest is againattained. A car provided with my improvement, on the contrary, movesback to or near its ordinary position, and then rests.

Some of the advantages of. my invention may be realized by elliptic orother forms of springs. I will describe simply what-I consider the bestmaterial `and lthe best form. Y

E is a cylindrical spring of vulcanized rubber, made hollow in thecenter, as usual. Itis partially inelosed within a rim, G1, formed on aplate, G, which is firmly bolted to the swing-beam, and is provided withslight projectionsordowels, g, which fit into shallow holes iu theswing-beam.

This plate G is, by preference, let into the side of the swing-beam, sothat its outer surface is flush therewith, but this is not absolutelyessential.

A flat plate, I, is correspondingly fitted on or in the ladjacentsurface of the truck-log, and a stellt shoeplate, H, of cast-iron orother suitable material, is fitted on the end of the spring E', so as toapply and rub against the rubbing-plate I.

' The shoe is provided with a rim, H, which incloscs a portion of therubber.

Both the castings G and 1I may, and should, by preference, have acentral boss, G and H2, which fits in the centr. l hole in the spring.

lhe bolting of the piece G may be largely effected by a single bolt, g',which applies Vthrough this boss G2, and, by extending through theswing-beam, may secure a corresponding plate, G, and spring, E', on thetwo faces of the swing-beam B. y

It will be readilyunderstood that, if preferred, the spring may besecured to the truck-log, and made to rub against the rubbing-plate Icarried on the swingbeam.

There muy also be more than two of the springs forward of and behind theswing-beam, or one alone placed in line of the center ofthe ear mightserve tolerably well in sonie instances. So, also, the spring and itsslioe may serve with some success, rubbing against bare wood, withoutany rubbing-plate I and, with the proper construction of steel spring,the friction might be borne fora considerable time by the spring itselfwithout lthe shoe 1I.

So, also, a portion of the advantages of my invention may be realized byemploying my spring on one face of the swing-beam B; as, for example, onthe front face, pressing the swing-beam B back to make a friet-iondirectly against the rear truck-log A2, or in rear pressing theswing-beam forward to make friction directly against the forwardtruck-log A, but I prefer the exact number and construction represented.

By making my springs of rubber, mounted and conneeted as shown, Iobtain, in addition to the other advantages, a good degree of resistanceto the transmission of sound, and the passengers hear less of the noiseof the wheels thanwhen there is a contact of hard inelastic substancesto conduct the sound.

I claim- 1. In railroad ear-trucks, the within-described arrangement ofsprings E' Eon one or both sides of the swing-beam B, whereby a constantand strong friction is maintained, to retard, without preventing theswinging motion of the beam, lelatively to the truck, and therebyrapidly arrest the lateral swinging of the ear, as herein specified.

2. The within-described construction of the springs E', holding-plate G'Glfa-nd shoe H Hl, as and for the purposes herein set forth.

3. The single bolt g', arranged as represented relatively to the centralbosses G2, of two holding-plates and two spr-ings on the forward andrear faces of the swing-beam B, as and for the purposes set forth.

In testimony whereof I have hereunto setmy name in presence of twosubscribing witnesses.

GEO. H. GRIGGS.

Witnesses l WM. C. DEY,

H. E. PRICE.

